Three-dimensional analysis of tunnels using infinite boundary elements

Abstract Methods of efficiently analyzing the three-dimensional state of stress and displacement in a rock or soil mass due to tunnelling is presented. The Boundary Element Method (B.E.M.) and the coupled BEM-Finite Element Method is used. Special infinite Boundary Elements are used to model the portion of the tunnel which is very long and can be assumed to extend to infinity. The methods are particularly efficient and accurate for determining the state of stress at the tunnel face and near tunnel intersections. A test example and a practical application in tunnelling is shown.